Keyboard Interface; Backlight And Illumination; Camera Concept; Camera Interface - Nokia RM-721 Service Manual

RM-721; RM-722
System Module

Keyboard interface

Figure 29 Keypad matrix

Backlight and illumination

The illumination has four main areas: numeric keypad (2 x white LEDs), display backlight (2 x white LEDs).
The display backlight is powered by the integrated DC/DC converter of the PEARL_J IC.
In the VLED+ line of the Pearl a "VLED disconnect switch" is integrated. This avoids that the VLED line is at
VBAT level even in switched off state (which can cause electro migration problems).
Figure 30 Backlight and illumination concept

Camera concept

Camera interface

The camera module is a EDOF 3.2 Mpix. The camera is connected directly to the baseband, no hardware
accelerator is used. Processing of the image is done by phone processor using NIPS (Nokia Imaging Perfection
System) algorithms.
The CCI-bus (Camera Command Interface) is an I2C-compatible interface that is used bidirectional to transfer
commands from BB to the camera and to get information of the camera register settings from the camera
to BB.
Issue 1 COMPANY CONFIDENTIAL Page 5 – 15
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